Silencer



March 31, 1936. R, L, NULTY Zg@ ASILENCER Filed June 17, 1955 INVENTGR.

OQQnnnnnou 1 l ATTORNEY.

Patented Mar. 31, 1936 UNITED STATES PATENT OFFICE 1 Claim.

This application relates to silencers and more particularly aims to provide a silencer of the resonating type.

The silencer here shown is characterized by the provision of spaced groups of holes in the inner and intermediate ones of the three shells used, which hole grouping and spacing has been found to give desirable operating characteristics to the silencer whereby the same silencer may be used on six cylinder enginesl and eight cylinder engines interchangeably and without sacrice of eciency.

For an understanding of the silencer here disclosed, reference should be had tol the appended drawing, whose Fig. 1 is a longitudinal section view of the silencer.

Referring to the drawing, it will be seen that the silencer there shown is of the straight through type wherein exhaust gases course through an innermost shell I without interruption from the inlet to the outlet thereof, there being an expansion chamber II formed at the outlet end of the silencer. Diaphragms I 2 connect and space the inner shell I 0' with respect to the intermediate shell I4 and an annular resonator chamber I5 spaces the intermediate shell I4 from the outermost shell I6.

In the construction shown, six diaphragms I2 are used, though this number may be varied as found desirable. For purposes of convenience the six diaphragms here shown are numbered I-6 and it is observed that the innermost shell is provided with a multiplicity of iine holes between the inlet end header I'I and diaphragm I, between diaphragms 2 and 3, and between diaphragms 4 and 5; the portions of the innermost shell between diaphragms I and 2, 3 and 4, and 5 and 6 are not so perforated. The intermediate shell is provided with a multiplicity of ne extruded holes arranged in groups with 5 the rst group being adjacent the inlet header Il, the second and third groups adjacent diaphragm 2, the fourth and fifth groups being adjacent diaphragms 4, and the sixth group being adjacent diap-hragm 6. The remaining portions 10 of the intermediate shell are left unperforated.

Due to the hole spacing and grouping shown, the silencer here shown operates satisfactorily and eihciently whether it be used on a six cylinder engine or upon an eight cylinder engine.

Now having described the silencer here shown, reference will be had to the claim which follows for a determination of the scope of the invention.

I claim:

A silencer including three relatively telescoped transversely spaced shells, inlet and outlet end headers closing the inlet and outlet ends of these shells, three or more longitudinally spaced diaphragms between the headers and connecting and spacing the innermost shell with respect to the intermediate shell, groups of holes on the innermost shell adjacent and on the silencer inlet sides of alternate ones of these diaphragms, said innermost shell being otherwise imperforate,

a group ofA holes on the intermediate shell adjacent and on the outlet side of the inlet header, groups of holes on the intermediate shell adjacent and on opposite sides of each diaphragm other than those mentioned as the alternate diaphragrns.

ROBERT L. NULTY. 

